Cumulative survival of IRF-8 KO, IRF-4/8 DKO, and IRF-4^+/−IRF-8^−/− mice and gross examination of moribund IRF-4/8 DKO mouse. (A) Survival curves were generated by Kaplan-Meier survival analysis. (B) Gross examination of a representative moribund IRF-4/8 DKO mouse showing massive ML, hepatosplenomegaly, and lymphadenopathy.